Variable Drive Vehicle

The versatility of current rovers and exploratory vehicles is limited by a single drive system. The Variable Drive Vehicle (VDV) employs a actuated systemcapable of switching between wheeled and tracked drive modes. This allows the vehicle to travel quickly and efficiently over smooth terrain and to traverse more arduous terrain by switching between these two systems. The small scale prototype built over the course of this project is equipped with two modular wheel driven track units to demonstrate the viability of the system. Electric linear actuators and servo motors allow for simple control and a smooth transition between each drive system. These devices allow the modular tracks to be rotated out from under the wheels, and stowed on the vehicle when not in use. Finite element analysis ensured that the VDV’s switchingmechanism maintains safe loading at its most critical points during a drive system transition. The VDV was tested on smooth concrete to determine its maximum wheel speed, track speed, and how fast the drive system could be switched. Experiments yielded a top speed of 11.5 mph in the wheel mode, 0.8mph in the track mode, and a switching time of 6.4 seconds. The vehicle’smaximumobstacle clearance, 1 inch in track mode and 2 inches in wheel mode, and slope, 5 degrees in track mode and 22 degrees in wheel mode, fell short of expected values. These shortcomings resulted from a poor frictional power transfer when attempting to power the tracks using the wheels. However, this prototype provides a proof of concept for a variable drive system successfully incorporating two drive systems, and future improvements may yield a promising platformfor future robotics research

Psychological Factors That Impact the Drop-Out Rate in Adolescent Sports

Children are dropping out of sport at alarming rates. With the highest numbers of dropout occurring between the ages of ten and seventeen, the focus of this research is on the drop-out rates of adolescents from sport. Athletic participation has been linked to positive academic performance, key development of leadership skills, and increased engagement in the community. The research that has been conducted related to sport persistence has had a greater focus on examining factors related to the physical domain. Attention is now beginning to shift however, and researchers are looking outside the physical domain and analyzing sport attrition more through sociological and psychological domains. The purpose of this research is to conduct a literary analysis on the psychological factors that impact the drop-out rate of adolescents from sport with adolescents being defined as children between the ages of ten and seventeen. Research in this domain is fairly limited; however numerous psychological theories have recently emerged as framework for conducting research as it relates to participation and drop-out in adolescent sports. These include self-determination theory, basic needs theory, achievement goal theory, and leisure constraints theory. The developmental model of sport participation is also a tool that is widely used to study sport persistence and drop-out. Foundationally based on psychology, this literature analysis was constructed to explore drop-out factors related to adolescent sport with the intent to collect data that either supports or disputes the relational connections between sport attrition or persistence. These relationships include but are not limited to the athlete/athlete, athlete/coach, athlete/parent, and athlete/self

Use of a putative maternal pheromone during transport and the effect of trailer temperatures on pig losses and welfare

The efficacy of a maternal pheromone (MP) to reduce transport stress was evaluated in a field study. In addition, we determined the appropriate field sample sizes for measures of death rate and the proportion of fatigued pigs observed before, during, and after transportation. In the first experiment, semi-truck trailers were randomly treated with 500 mL of MP or isopropyl alcohol as the control (C). Animal handling measures were collected at truck loading, unloading, and from resting pens to the stun area. Blood samples were collected from a sample of transported pigs. In the second experiment, a single truck was used repeatedly for transport to the slaughter plant. The truck and lairage pens were sprayed either with the MP or C, depending on the week (n = 11 weeks). Rate of fatigued pigs coming off the truck was 0.41% for C-treated pigs and 0.15% for MP-treated pigs (P > 0.05). Air temperature recorded in the trailers rose during truck loading and idle time, but levelled off during driving (holding at 1.7°C greater than outside). MP tended to reduce the rate of fatigued pigs (39% although not statistically significant) but it also increased handling difficulty. A power test indicated the sample size needed to detect differences with a statistical significant magnitude (P 0.05). Air temperature recorded in the trailers rose during truck loading and idle time, but levelled off during driving (holding at 1.7°C greater than outside). MP tended to reduce the rate of fatigued pigs (39% although not statistically significant) but it also increased handling difficulty. A power test indicated the sample size needed to detect differences with a statistical significant magnitude (

The framing of social class distinctions through family food and eating practices

The definitive version can be found at: http://onlinelibrary.wiley.com/ Copyright 2011 The Authors, the Sociological Review 2011 and The Editorial Board of The Sociological ReviewDrawing on two qualitative studies which looked at diet, weight and health from a social class perspective, we use Bourdieu's theory of habitus to help explain the different food and eating practices undertaken by families with young teenagers. Whilst the families displayed considerable reflexivity when making decisions about what to eat on a daily basis, the analysis highlighted that everyday behaviours are still bounded by distinctions of taste, according to social position. The paper includes an examination of the relationships between different forms of capital and whether form or functionality is prioritised within families. We show the importance of temporal frameworks when interpreting classed food and eating practicesPeer reviewe